Natural stones for monuments: their availability for restoration and evaluation
This paper represents the introduction to the volume focused on the various aspects of natural stone research. From the topic issues studied recently, four major aspects are covered: (1) availability of certain stone types for monuments, (2) strategies aiming to strengthen our knowledge of past resources through the establishment of natural stone databases and inventories, (3) evaluation of natural stone properties and assessment of the compatibility of repair stones, and (4) decay studies of natural stone on monuments and on natural exposures. This paper also aims to highlight the importance of the use of local stone resources, a practice that has seriously declined during the 20th century in most of the industrialized countries. The availability of natural stone from monuments is also discussed in terms of sandstones and travertine in the Czech Republic and Hungary as a typical example.